In recent years, wireless projectors have become widely used where an image displayed on an information-processing apparatus such as a personal computer (also abbreviated simply as PC, hereinafter) and a digital camera is transferred through a wireless network (particularly wireless LAN) using radio waves, not through a cable such as a RGB cable and USB cable, and the image is projected on a screen.
This situation is against the following background. That is, with the extensive spread of information-processing apparatus such as a notebook PC with high portability and a digital camera, the demand is growing for easily connecting an information-processing apparatus carried while moving around in a room to a projector placed on the spot. Further, compared to conventional cable connection, the degree of flexibility significantly increases in the installation location of a projector and an information-processing apparatus. For example, a projector placed at a remote location (e.g. the ceiling of a meeting room) can be easily connected.
To use a wireless network, a wireless LAN adaptor as hardware is required, and its driver and a software program for specifying a communication target (i.e. projector) need to be installed in the information-processing apparatus.
To install a program in a PC, a CD-ROM attached with the hardware device needs to be inserted into the CD-ROM drive of the PC for installing the device driver and setting programs.
This installation work is troublesome and requires an external CD-ROM drive separately for a PC without a CD-ROM drive. Examples of how to simplify such a troublesome operation include those described in patent literatures 1 and 2.
Patent literature 1 describes the following way. That is, a wireless LAN adaptor (usually called a dongle) has a function of being recognized as a keyboard when connected to a USB terminal of a PC, and allows any file in the wireless LAN adaptor to be loaded on the PC for execution. After that, the keyboard function is changed to the wireless LAN adaptor function for being used as a regular wireless LAN adaptor.
Patent literature 2 describes an information-processing apparatus (a projector-supporting peripheral device in the literature) such as a digital camera that searches only for company's own-brand projectors through a wireless LAN and selects one to be connected from them. The apparatus, when the search button is pressed, searches for projectors having an SSID (service set identifier) specific to a company's own-brand projector, and indicates respective connection states (state of connection and disconnection to and from another device) using a combination of the number of light-emitting LEDs and their emission colors. When the user presses the select button, the apparatus establishes connection with a desired wireless projector.
A projector is fixedly installed in a room of a building. Particularly in such as an office, more than one projectors are installed. In this case, a projector is used by specified or unspecified people, and thus a projector unique to a room needs to be easily connected with their PCs. This condition can be satisfied if a dongle-type wireless LAN adaptor is issued or lent to a user as a wireless LAN adaptor dedicated to the projector.
A dongle-type wireless LAN adaptor, however, is small and lightweight enough to be carried so easily, and thus a user may accidentally use an adaptor for a projector different from a desired one. In such a case, a PC cannot be connected to a desired projector. If a projector corresponding to the wrong adaptor is placed in such as a next room, the PC ends up being connected to the projector, which may cause a large problem in information security.
If only one projector with the same SSID is present in a range where wireless communication with a PC is possible (a range that radio waves reach), the PC can detect a desired projector to connect to the projector reliably. Meanwhile, if plural projectors with the same SSID are present and they belong to network groups with different wireless channels (also referred to simply as channel, hereinafter), the PC cannot detect a projector to be connected. That is, by the conventional search method, an SSID is set to a PC, and the PC scans channels in a predetermined order to search for a projector connected to the same network group. Then, the PC communicates with a projector detected for the first time; checks if the projector is one to be connected; and stops the search at the point if the projector is not one to be connected. Consequently, even if a projector to be connected is present in the same network group, the PC is unable to connect to the projector.